Answer:
D
Step-by-step explanation
Let x be the cost of 1 lb of grapes and y be the cost of 1 lb of oranges
Then,
2x + 4y = $ 10.70
3x + 2y= $9.65
The value of an equation doesn't change if we multiply both L.H.S and R.H.S by the same number.
3(2x + 4y) = 3 * $10.70
6x + 12y = $32.10 .............(1)
2( 3x + 2y) = 2 * $ 9.65
6x + 4y = $19.30 ..........(2)
Using elimination method, (1) - (2),
6x + 12y - (6x + 4y) = $32.10 - $19.30
6x + 12y -6x -4y = $ 12.80
8y = $12.80
y = ($12.80)/8
Therefore, y = $1.60
The cost of 1 lb of oranges = y = $1.60
2x + 4y = $ 10.70
2x + 4 * $1.60 = $ 10.70
2x + $6.40 = $10.70
2x = $10.70 - $6.40
2x = $4.30
x = $2.15
The cost of 1 lb of grapes = x = $ 2.15
Hope it helps : )
Any doubts?